1. Field of the Invention
The present invention relates to a navigation system capable of registering a telephone number for a set point.
2. Related Art
A navigation system guides a user along a route so that the user can drive his car safely to a first destination. In recent years, techniques for improving the performance and functions such as accuracy, operability and visibility of navigation have been vigorously pursued, resulting in a variety of systems. A typical navigation system is equipped with a display screen to be used for setting the route, to be opened automatically or upon request of the driver at the time of route guidance. The navigation system provides, on its display screen after the start of guidance, at least: section maps for guidance over a wide area covering several sections of the set whole route, including the section currently being travelled; and an intersection map for guidance at intersections.
The navigation system not only displays section maps and intersection maps but also: provides the remaining distance and information such as the name or turning direction for an intersection, so that the route may be followed without fail; teaches landmarks so that the route can be confirmed during the drive; guides along the route not only by visual display but also by voice; displays the route on the map so that the guidance may be provided on the displayed route for the actual drive; and scrolls the map automatically along the route so that the route can be confirmed.
In such navigation systems, in order to set the route, it is necessary to input the starting point and the destination. When the starting point and the destination are input, route retrieval is executed from the road information data around and between the starting point and the destination, so that the optimum of a plurality of routes is set. As the method of inputting the starting point and the destination, there have been proposed: a method by which the positions to be registered such as the starting point or the destination are classified by genre, e.g., sight-seeing, parking areas or restaurants, or coded according to the areas such as prefectures or cities so that the codes may be input; a method by which not only the code number is input but also a menu is displayed so that the items in the menu may be sequentially selected and input; a method by which node data are joined to define road networks so that the position may be input in terms of east longitudes and north latitudes; and a method by which a telephone number is input. In another method, not only the route between two points of the present position (or an arbitrary staring point) and the destination is retrieved, but also the priority of the transit point or the toll road is specified for retrieval.
As examples of the system of this kind: a telephone number inputting system is disclosed in Japanese Patent Laid-Open No. 187898/1990; a genre or code number inputting system is disclosed in Japanese Patent Laid-Open No. 173820/1989; a destination setting system according to the code number is disclosed in Japanese Patent Laid-Open No. 173823/1989; and a system capable of inputting the desired transit point is disclosed in Japanese Patent Laid-Open No. 3899/1990.
For the telephone number inputting system, however, as a practical matter it is difficult to store identification of locations corresponding to all telephone numbers in the memory, because the data is excessively massive. In the system of the prior art, therefore, the locations corresponding to specific telephone numbers and the positions of representative points for areas corresponding to toll/local exchange (area code) are stored as data in a CD-ROM or the like. When an input telephone number is specifically matched with stored data, the map around the position corresponding to that telephone number is displayed on the screen. For other telephone numbers, however, the map around the representative point of the toll/local exchange number is displayed.
In case, therefore, a telephone number of a personal subscriber is input, the map displayed is for the area around the representative point for the toll/local exchange number. Thus, there arises a problem that the positional accuracy in the calling up of the map is insufficient.